//designpatterns.abstractfactory.XMLUtil.java
package abstractfactory;

import javax.xml.parsers.*;
import org.w3c.dom.*;
import java.io.*;

public class XMLUtil {
	//该方法用于从XML配置文件中提取具体类类名，并返回一个实例对象
	public static Object getBean() {
		try {
			//创建DOM文档对象
			DocumentBuilderFactory dFactory = DocumentBuilderFactory.newInstance();
			DocumentBuilder builder = dFactory.newDocumentBuilder();
			Document doc;
			doc =builder.parse(new File("src//designpatterns//abstractfactory//config.xml"));

			//获取包含类名的文本结点
			NodeList nl = doc.getElementsByTagName("className");
			Node classNode=nl.item(0).getFirstChild();
			String cName=classNode.getNodeValue();

			//通过类名生成实例对象并将其返回
			Class c=Class.forName(cName);
			Object obj=c.newInstance();
			return obj;
		}
		catch(Exception e) {
			e.printStackTrace();
			return null;
		}
	}
}
